Weather & Climate, Synoptic Charts,Weather Maps

1. Weather Maps Weather & Climate

9. Atmospheric Pressure readings How do they get the land and sea readings? What do all these dots form when they are linked?

10. Isobars How do you work out which are high pressure cells and which are low pressure cells? An isobar is a line on a map joining places of equal atmospheric pressure

12. Synoptic Charts Synoptic Charts What is this feature? What does the shading refer to? What is the wind speed and direction? What is the air pressure?

18. Highs can bring rain from onshore warm waters

23. A cross section of a Tropical Cyclone

24. Cyclone Larry 2006

28. Note the closeness of the isobars Note the spaced isobars

29. Reading Wind Direction on a Weather Map Not where its going too x Sydney N Close up of a map Easterly √ (Remember that we name our wind direction on where the wind came from )

30. How to Read Wind Speed on a Weather map Legend- Wind Speed 5 km/hr 10 km/hr 20 km/hr To work out the wind speed of an area, all you need to do is match up the wind speed symbol found on the map with the symbol found in the key The wind speed at point A is 5 km/hr A 30 km/hr Calm

32. Wind direction Remember we always refer to where the wind is coming from ! Where has the wind come from? 1 2

34. Wind blows outwards in an anticlockwise direction in areas of high pressure. ANTI CYCLONE = ANTI CLOCKWISE WINDS.

36. Winds blow towards the centre of a low pressure system and in a clockwise direction LO W P. C. = CYC LO NE = C LO CKWISE WINDS.

39. How do you read wind direction without windsticks? The black arrows show the wind direction. High and low pressure regions do not stay in the same place. They move over the Earth's surface.

41. A warm front

42. Cold fronts are far more common in Australia and occur when cold air is pushed into a warm air mass . This forces the warm air to rise causing a number of changes: (a) Decrease in temperature : cold air replaces warm air. (b) Change in wind direction and sometimes speed. (c) Build up of cumulonimbus or rain bearing clouds . (d) Increase in humidity : corresponding to a build up of clouds. (e) Probability of rain . Make up an acronym to remember these changes.

43. A cold front

47. Types of rainfall: Convection http://www.youtube.com/watch?v=RkgThul2El8

48. Types of rainfall: Orographic http://www.youtube.com/watch?v=BVykQfRC_aI http://www.radioblogclub.com/open/51998/elevation_u2/U2_-_Elevation

49. Orographic Rainfall The dry air mass becomes warmer, with little chance of rain. Deserts are often found on the leeward side of large mountain ranges Warm moist air approaches a mountain barrier The air mass is forced to rise as it hits the mountain and condenses into clouds Orographic rainfall occurs on the windward side of the mountains The air mass, now drier, flows down the leeward side of the mountains

50. Types of rainfall: Frontal http://www.youtube.com/watch?v=D88dYNFyBq8 http://www.bbc.co.uk/schools/gcsebitesize/geography/weather/elementsofweatherrev6.shtml

53. Summer weather map Where are the different cells located?

54. Winter weather map Where are the different cells located?

55. Clear skies allow the sun’s rays to have maximum effect. Daytime temperatures are usually high. At night, clear skies allow heat to be lost causing temperatures to fall. In winter frosts are likely.

56. Why Do Climates Vary?

57. Factors Affecting The Climate What makes a certain place hot, cold, wet, dry, windy…?

59. World Pattern of Climate The climate of a particular place on the earth’s surface depends on 5 main factors. Latitude: Affects temperature radiation from the sun is stronger and more direct at the equator. Places at the equator are therefore generally hotter than the places near the poles. Also seasonal differences are more obvious away from the equator. Now copy fig 5.3e from p109 in your text

61. Differential Heating. At the Poles the sun’s rays covered a larger surface area, therefore heating is less efficient. At the Equator, the sun’s rays covered a smaller surface area, therefore heating is more efficient. At the Equator the sun’s rays also have to travel through less of the Earth’s atmosphere, therefore more heat energy reaches earth.

64. Why are the temperatures different? Relief Everest. The higher the relief (elevation), the lower the temperature, about 6degrees C for each 1000 metres.

69. Gulf Stream Then there are air masses... Also known as the North Atlantic Drift . A current of warm water that travels from the Gulf of Mexico . This, along with the prevailing South-Westerly wind , enables a relatively warmer climate compared to areas on the same latitude .

73. Continentality Sea heats up slowly and cools slowly. Land heats up quickly and cools quickly.